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SUMMARY

A 26-year-old male tower erector (the
victim) died after falling 125 feet from a cellular phone tower. The victim was a member
of a five-man crew that was erecting a 250-foot cellular phone tower. The victim was on
the tower with another tower erector working from top to bottom, securing flexible
electrical cables to two of the tower legs. The cables would supply power for the tower's
satellite and beacon lights. The victim and foreman climbed down diagonal and horizontal
tower cross-members from the 145-foot level to the 125-foot level and began to secure
their positioning lanyards to the horizontal tower members. The victim was holding onto a
horizontal tower member as he reached to secure his lanyard to the tower. The other
erector, located 8 to 10 feet from the victim, heard the victim yell and saw him fall to
the ground. The victim struck a metal electrical switch box and its concrete mounting pad
prior to hitting the ground. A worker on the ground ran to the truck and called the
emergency medical service (EMS). The county EMS and county coroner responded, and the
coroner pronounced the victim dead at the scene. NIOSH investigators concluded that, to
prevent similar occurrences, employers should:

instruct workers to maintain 100% fall
protection while on towers

instruct workers to take sufficient rest
periods to decrease the risk of fatigue.

INTRODUCTION

On March 29, 1998, a 26-year-old male
tower erector (the victim) died after falling 125 feet from a cellular phone tower. On
April 6, 1998, officials of the South Carolina Occupational Safety and Health
Administration (SCOSHA) notified the Division of Safety Research (DSR) of the fatality,
and requested technical assistance. On April 14, 1998, a DSR Occupational Safety and
Health Specialist conducted an investigation of the incident. The incident was reviewed
with the SCOSHA compliance officer assigned to the case, the president and vice-president
of the company, and the county coroner. The incident site was visited and photographed
during the investigation.

The employer was a tower erection
contractor that had been in operation 3 years and employed eight workers. The company had
a written safety policy and manual that covered all aspects of general construction. Since
the incident, the employer is working with the safety directors of other tower erection
contractors to develop a fall protection plan specific to tower erection. Pre-construction
site surveys were conducted by the vice-president and the crew foreman. Tailgate safety
meetings were conducted prior to work beginning on each job and on an as needed basis
thereafter. The victim had worked for the employer for 6 days, but had 6 years of
documented experience as a tower erector.

INVESTIGATION

The employer had been sub-contracted to
erect the steel structure for a three-legged, 250-foot-high cellular phone tower. Site
preparation had been completed. This included clearing the ground, pouring the concrete
footers for the tower legs, setting an electrical switch box for the tower's beacon lights
and satellite, and erecting an 8-foot chain link fence around the perimeter of the tower.

The five-man crew consisted of three tower
erectors(including the victim), a groundman, and a foreman. The crew assembled 20-foot
sections of the tower on the ground prior to the arrival of a crane that would lift the
sections into place. Each section consisted of three 20-foot legs, with horizontal and
vertical cross braces between the legs, forming three faces on each section. After the
crane arrived on site, two erectors worked on the tower, while the third erector,
groundman, and foreman assembled the remaining 20-foot tower sections.

At the time of the incident, the tower
structure had been completed, and the tower's beacon lights and satellite had been
installed. The only remaining task was to install the flexible electrical cables that
would power the lights and satellite and secure them to the tower legs from the top to the
bottom. Electricians would then wire the cables into the switch box.

Prior to leaving the site, the crane
lifted the cables to positions near the satellite and the beacon lights. The two tower
erectors then wired the cables into the satellite and lights.

The two tower erectors (including the
victim) started at the top of the tower and climbed down, attaching the cables to the
tower legs at approximately 15-foot intervals with plastic zip ties. The tower erectors
each wore a 6-foot lanyard equipped with a large pelican hook attached to their body
harnesses, which they used as positioning devices to attach to the tower when they stopped
to secure the cables. The men free-climbed down the vertical and horizontal cross braces
on their way down the tower.

The men secured the cables at the 140-foot
level and climbed down to a level approximately 125 feet above ground. The victim was
standing on a horizontal cross brace and holding onto the tower leg with his left hand
while trying to attach his lanyard to a horizontal cross member with his right hand. The
other tower erector, positioned 8 to 10 feet from the victim, heard the victim yell and
looked over to see the victim fall away from the tower. The victim fell to the ground,
striking the electrical switch box and the concrete pad on which the switch box was
mounted. The foreman summoned the emergency medical service from a mobile phone in his
truck. The county EMS responded with the county coroner, who pronounced the victim dead at
the site. During interviews with the OSHA compliance officer, the tower erector who was on
the tower with the victim at the time of the incident, stated that it looked like the
victim's left hand cramped as he was attempting to attach his lanyard to the tower. The
victim's left hand drew away from the tower, leading to the fatal fall.

CAUSE OF DEATH

The county coroner listed the cause of
death as massive trauma to the head and trunk.

RECOMMENDATIONS/DISCUSSION

Discussion: In this case, the employee
fell from the tower after he apparently was attempting to connect his fall protection in
order to be tied off while securing the electrical cables. Employers should instruct tower
workers to maintain 100% fall protection during tower construction. One hundred percent
fall protection is defined as follows: every employee at risk of fall from work levels
over 6 feet above the ground or working surface must be protected by some conventional
means of fall protection, which may include an integral fall-arrest system. This applies
to ascending, descending, moving point to point, or any tower construction or alteration
work activity conducted at an elevated work station. Employers should also require a
minimum of three-point contact (two hands and one foot or two feet and one hand) at all
times.

Traditional fall protection for this job
is more effective when the employee is stationary and tied onto the structure. It is
recommended that other methods of fall protection be used that protect employees while
they are moving as well as when stationary. Employees should be equipped with two lanyards
so that while moving from point to point, one lanyard will be connected to the tower at
all times. Additionally, a lifeline system or cable safety-climb device attached to the
highest point of the tower leg provides a tie-off point for the employee to hook onto, and
provides fall protection coverage at all times. For a tower leg or similar vertical
structure, a fall arrester (e.g., rope grab) should be worn by the employee and attached
to the lifeline, enabling the worker to move freely without interference until a free fall
is detected. If these types of fall protection are not feasible, safety nets should be
installed at the worksite in accordance with 29 CFR 1926.105(a)which states that safety
nets shall be provided when workplaces are more than 25 feet above the ground where the
use of ladders, scaffolds, catch platforms, temporary floors, safety lines, or safety
belts is impractical.

Recommendation #2: Employers should
instruct workers to take sufficient rest periods to decrease the risk of fatigue.

Discussion: In this instance, the victim's
arm may have cramped, causing him to lose his grip on the tower. When a climber is
prepared to begin a climb, they should attach to a functional safety climb device. The
techniques involved in ascending or descending a tower are very basic. When a climber
moves up or down a permanent step or a member of the tower structure, the climber's legs
should carry most of the weight. The arms and hands should be used only to maintain
balance and the climber's position. Whenever possible, a climber should remain on the
outside of the graduated slope of the tower. Using this method, the climber is naturally
pulled toward the structure, lessening the effects of fatigue. Climbers should be
instructed to limit their climbing runs (distances without stopping) to a comfortable
distance, stopping before they begin to feel the effects of fatigue.